1. Field of the Invention
The present invention relates to a means and method for eliminating the creases which are formed during coiling in the initial wraps of wound or coiled materials by the lead or head end of the material. When winding or coiling materials onto the mandrels of tension reels, creases are often promulgated through the first several wound layers because the lead or head end of the material which rests on the mandrel transmits its impression into the initial layers.
Those lengths of the coiled material having creases in them cannot be used to make finished parts whose acceptability depends upon their having a smooth unblemished surface. The electrogalvanized steel sheet which is used for exposed panels in automobiles, refrigerators, washing machines and the like is one such material which in its processing must be coiled and is susceptible to creasing. For ease of explanation, this invention will be described with respect to electrogalvanized steel although it should be understood that it is applicable to other materials which are susceptible to creasing when coiled such as, for example, aluminum, copper, plastic and the like.
In the case of electrogalvanized steel strip, the head of the coil causes an impression the width of the coil to be transmitted through about the first 100 laps, or several inches, of the coil inner diameter as it is wrapped on the tension reel. This impression causes surface defects in the finished product which result in about 180 to 300 feet of steel strip having to be scrapped.
The instant invention entirely eliminates the problem of creasing by advantageously employing a combination of proximity sensors and a unique mandrel sleeve adaptor, or boot, having a narrow soft zone disposed therein. The instant invention advantageously coordinates the head end of the strip with the soft zone on the mandrel sleeve adaptor to quickly and effectively wind or coil the material while eliminating the problem of creasing.
2. Description of Related Art
The broad concept of providing a mandrel or tension reel with a soft covering to avoid creasing in subsequent wraps is known. Moreover, dual hardness mandrel sleeves have been used which have a firm inner coating covered by a soft outer coating. These attempts, however, have not adequately solved the problem of creasing because they do not provide for the head end of the strip to be embedded in the sleeve or boot to a significantly greater extent than the rest of the strip. With prior art methods, the entire boot is compressed. If the strip is tightly wound the compressed rubber boot cannot absorb the head end and a crease is formed in subsequent wraps. If the strip is wound loosely, the inner diameter of the coil collapses and the customer can not insert their mandrel for subsequent uncoiling of the product.